US8838363B2 - Method for injecting fuel - Google Patents

Method for injecting fuel Download PDF

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US8838363B2
US8838363B2 US13/356,843 US201213356843A US8838363B2 US 8838363 B2 US8838363 B2 US 8838363B2 US 201213356843 A US201213356843 A US 201213356843A US 8838363 B2 US8838363 B2 US 8838363B2
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Prior art keywords
fuel
intake
egr
adjusting
amount
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US20130191008A1 (en
Inventor
Gopichandra Surnilla
Richard E. Soltis
James Michael Kerns
Stephen B. Smith
Imad Hassan Makki
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Ford Global Technologies LLC
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Ford Global Technologies LLC
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Priority to US13/356,843 priority Critical patent/US8838363B2/en
Assigned to FORD GLOBAL TECHNOLOGIES, LLC reassignment FORD GLOBAL TECHNOLOGIES, LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KERNS, JAMES MICHAEL, MAKKI, IMAD HASSAN, SMITH, STEPHEN B., SOLTIS, RICHARD E., SURNILLA, GOPICHANDRA
Priority to RU2013100987A priority patent/RU2609016C2/ru
Priority to DE102013200830A priority patent/DE102013200830A1/de
Priority to CN201310027468.5A priority patent/CN103216351B/zh
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1439—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the position of the sensor
    • F02D41/144—Sensor in intake manifold
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D41/003—Adding fuel vapours, e.g. drawn from engine fuel reservoir
    • F02D41/0042—Controlling the combustible mixture as a function of the canister purging, e.g. control of injected fuel to compensate for deviation of air fuel ratio when purging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D2041/1472—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being a humidity or water content of the exhaust gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/04—Introducing corrections for particular operating conditions
    • F02D41/08—Introducing corrections for particular operating conditions for idling

Definitions

  • the present disclosure relates to fuel injection in an engine.
  • Fuel injection amounts are typically set based on a desired air/fuel ratio and adapted using feedback from one or more exhaust gas sensors in the exhaust. Fueling errors may occur, however, during operating conditions where fuel vapors are present in the intake. For example, fuel vapor canisters designed to trap fuel vapors from the fuel tank are periodically purged to the intake, and these vapors may result in an excess amount of fuel in the cylinders, wasting fuel and degrading emissions.
  • a method comprises adjusting fuel injection based on fuel concentration in an engine intake manifold, and during idle and when EGR is disabled, adjusting fuel injection based on the fuel concentration and a fuel pushback amount.
  • fuel injection may be adjusted based on fuel vapors present in the intake, for example, from both a fuel vapor canister purge and from a positive crankcase ventilation system. In one example, these fuel vapor amounts may be determined based on an oxygen sensor present in the intake. Further, the fuel injection may be additionally adjusted based on an amount of pushback fuel, for example from fuel evaporated from a fuel puddle on an intake valve or port.
  • fuel injection amounts may be adjusted to maintain desired air/fuel ratio in the cylinder.
  • the intake oxygen concentration may be able to provide an indication of an amount of ambient humidity, fuel vapors from various sources, and/or an amount of exhaust gas recirculation in the intake.
  • optimal air/fuel ratio may be maintained, improving fuel economy and reducing emissions.
  • the amount of vapors can also be adjusted based on feedback from exhaust air-fuel ratio sensors, purge flow estimates, purge duration, and other parameters if desired.
  • FIG. 1 shows an example engine system according to an embodiment of the present disclosure.
  • FIG. 2 shows a single cylinder of the multi-cylinder engine of FIG. 1 .
  • FIG. 3 shows flow chart illustrating a high level control routine for adjusting fuel injection based on feedback from an intake oxygen sensor according to an embodiment of the present disclosure.
  • FIGS. 4A-4C show flow charts illustrating a control routine for correcting a fuel concentration amount according to an embodiment of the present disclosure.
  • FIG. 5 shows an example diagram illustrating a relationship between an intake oxygen concentration and an intake fuel concentration.
  • An oxygen sensor positioned in the intake of an engine may be able to provide information regarding various parameters of the intake air, including ambient humidity, EGR, and fuel vapor amounts in the intake. Under some conditions, the reading from the intake oxygen sensor may be directly used to determine one or more of the above parameters. In other conditions, the intake oxygen amount may be determined and the relative contribution of the above parameters to the intake oxygen concentration may be modeled. Together, this information may be used to maintain the air/fuel ratio in each cylinder at an optimal level to improve fuel economy and reduce emissions.
  • FIG. 1 is an example engine system including a controller, an intake oxygen sensor, and various sources of intake fuel vapors, such as a fuel tank vapor recovery system.
  • FIG. 2 is a single cylinder diagram of the engine of FIG. 1 .
  • FIG. 3 and 4 A- 4 C are example control routines that may be carried out by the controller of FIG. 1 to adjust fuel injection based on the intake oxygen sensor during various engine operating conditions.
  • FIG. 5 is a graph illustrating the relationship between intake oxygen concentration and fuel vapor amounts present in the intake.
  • FIG. 1 shows aspects of an example engine system 1 for a motor vehicle.
  • the engine system is configured for combusting fuel vapor accumulated in at least one component thereof.
  • the engine system includes engine 10 .
  • Engine 10 may be virtually any volatile-liquid or gas-fueled internal combustion engine, e.g., a port- or direct-injection gasoline engine or diesel engine.
  • the engine may be adapted to consume an alcohol-based fuel—ethanol, for example.
  • Engine system 1 includes at least two sensors depicted in FIG. 1 : manifold gas sensor 24 fluidically coupled to an air conduit downstream of throttle 62 , and humidity sensor 26 fluidically coupled to an air conduit upstream of throttle 62 .
  • Sensor 24 may be any suitable sensor for providing an indication of intake gas concentration, such as a linear oxygen sensor or UEGO (universal or wide-range exhaust gas oxygen), a two-state oxygen sensor or EGO, a HEGO (heated EGO), a NOx, HC, or CO sensor. Additional sensors not shown in FIG. 1 may also be present, such as MAP, MAF, and temperature sensors.
  • controller 12 which may be any electronic control system of the engine system or of the vehicle in which the engine system is installed. Accordingly, the electronic control system may be configured to make control decisions, actuate valves, etc., based at least partly on the gas concentrations sensed within the engine system. Additional information regarding controller 12 will be presented with respect to FIG. 2 below.
  • Intake manifold 44 is configured to supply intake air or an air-fuel mixture to a plurality of combustion chambers of engine 10 .
  • the combustion chambers may be arranged above a lubricant-filled crankcase 130 , in which reciprocating pistons of the combustion chambers rotate a crankshaft.
  • the reciprocating pistons may be substantially isolated from the crankcase via one or more piston rings, which suppress the flow of the air-fuel mixture and of combustion gasses into the crankcase. Nevertheless, a significant amount of fuel vapor may ‘blow by’ the piston rings and enter the crankcase over time.
  • crankcase may be continuously or periodically ventilated, as further described hereinafter.
  • post-throttle crankcase-ventilation valve 132 controls the admission of ventilation air into the crankcase.
  • the post-throttle crankcase-ventilation valve may be any fixed or adjustable portioning valve.
  • Engine system 1 includes fuel tank 34 , which stores the volatile liquid fuel combusted in engine 10 .
  • the fuel tank is vented to the atmosphere through adsorbent canister 136 .
  • the adsorbent canister may have a significant capacity for storing hydrocarbon-, alcohol-, and/or ester-based fuels in an adsorbed state; it may be filled with activated carbon granules and/or another high surface-area material, for example. Nevertheless, prolonged adsorption of fuel vapor will eventually reduce the capacity of the adsorbent canister for further storage. Therefore, the adsorbent canister may be periodically purged of adsorbed fuel, as further described hereinafter.
  • post-throttle canister-purge valve 138 controls the admission of purge air into the adsorbent canister.
  • adsorbent canister 136 is coupled to the fuel tank via refueling tank vent 140 .
  • the refueling tank vent may be a normally closed valve which is held open during refueling.
  • engine-running tank vent 142 is provided.
  • the engine-running tank vent may be a normally closed tank vent which is held open while the engine is running.
  • the engine-running tank vent when open, may conduct vapors from the fuel tank to the intake manifold via buffer 144 .
  • the buffer may be any structure configured to reduce or restrict the admission of transient slugs of fuel vapor into the clean air intake conduit. Such slugs of fuel vapor could be caused by tank slosh, for example.
  • the buffer may comprise one or more baffles, screens, orifices, etc.
  • FIG. 1 ensures that during refueling, air from fuel tank 34 , now stripped of fuel vapor, may be vented to atmospheric pressure.
  • refueling tank vent 140 and engine-running tank vent 142 may be closed so that it can be determined whether some isolated part of engine system 1 can hold pressure or vacuum.
  • throttle 62 , post-throttle crankcase-ventilation valve 132 , post-throttle canister-purge valve 138 , and tank vents 140 and 142 may be electronically controlled valves operatively coupled to controller 12 to facilitate such diagnostics, and other features of engine operation.
  • post-throttle crankcase-ventilation valve 132 is shown coupled to intake manifold 44 and to crankcase 130 via intake-protecting oil separator 146 .
  • the direction of ventilation air flow through the crankcase depends on the relative values of the manifold air pressure (MAP) and the barometric pressure (BP).
  • MAP manifold air pressure
  • BP barometric pressure
  • FIG. 2 is a schematic diagram showing one cylinder of multi-cylinder engine 10 , which may be included in a propulsion system of an automobile.
  • Engine 10 may be controlled at least partially by a control system including controller 12 and by input from a vehicle operator 2 via an input device 4 .
  • input device 4 includes an accelerator pedal and a pedal position sensor 6 for generating a proportional pedal position signal PP.
  • Combustion chamber (i.e., cylinder) 30 of engine 10 may include combustion chamber walls 32 with piston 36 positioned therein. Piston 36 may be coupled to crankshaft 40 so that reciprocating motion of the piston is translated into rotational motion of the crankshaft.
  • Crankshaft 40 may be coupled to at least one drive wheel of a vehicle via an intermediate transmission system.
  • a starter motor may be coupled to crankshaft 40 via a flywheel to enable a starting operation of engine 10 .
  • Combustion chamber 30 may receive intake air from intake manifold 44 via intake passage 42 and may exhaust combustion gases via exhaust passage 48 .
  • Intake manifold 44 and exhaust passage 48 can selectively communicate with combustion chamber 30 via respective intake valve 52 and exhaust valve 54 .
  • combustion chamber 30 may include two or more intake valves and/or two or more exhaust valves.
  • intake valve 52 and exhaust valves 54 may be controlled by cam actuation via respective cam actuation systems 51 and 53 .
  • Cam actuation systems 51 and 53 may each include one or more cams and may utilize one or more of cam profile switching (CPS), variable cam timing (VCT), variable valve timing (VVT) and/or variable valve lift (VVL) systems that may be operated by controller 12 to vary valve operation.
  • the position of intake valve 52 and exhaust valve 54 may be determined by position sensors 55 and 57 , respectively.
  • intake valve 52 and/or exhaust valve 54 may be controlled by electric valve actuation.
  • cylinder 30 may alternatively include an intake valve controlled via electric valve actuation and an exhaust valve controlled via cam actuation including CPS and/or VCT systems.
  • Fuel injector 66 is shown coupled directly to combustion chamber 30 for injecting fuel directly therein in proportion to the pulse width of signal FPW received from controller 12 via electronic driver 68 . In this manner, fuel injector 66 provides what is known as direct injection of fuel into combustion chamber 30 .
  • the fuel injector may be mounted in the side of the combustion chamber or in the top of the combustion chamber, for example. Fuel may be delivered to fuel injector 66 by a fuel system (not shown in FIG. 2 ) including a fuel tank, a fuel pump, and a fuel rail.
  • combustion chamber 30 may alternatively or additionally include a fuel injector arranged in the intake in a configuration that provides what is known as port injection of fuel into the intake port upstream of combustion chamber 30 .
  • Intake passage 42 may include a throttle 62 having a throttle plate 64 .
  • the position of throttle plate 64 may be varied by controller 12 via a signal provided to an electric motor or actuator included with throttle 62 , a configuration that is commonly referred to as electronic throttle control (ETC).
  • ETC electronic throttle control
  • throttle 62 may be operated to vary the intake air provided to combustion chamber 30 among other engine cylinders.
  • the position of throttle plate 64 may be provided to controller 12 by throttle position signal TP.
  • Intake passage 42 may include a mass air flow sensor 120 and a manifold air pressure sensor 122 for providing respective signals MAF and MAP to controller 12 .
  • Ignition system 88 can provide an ignition spark to combustion chamber 30 via spark plug 92 in response to spark advance signal SA from controller 12 , under select operating modes. Though spark ignition components are shown, in some embodiments, combustion chamber 30 or one or more other combustion chambers of engine 10 may be operated in a compression ignition mode, with or without an ignition spark.
  • Exhaust gas sensor 126 is shown coupled to exhaust passage 48 upstream of emission control devices 71 and 72 .
  • Sensor 126 may be any suitable sensor for providing an indication of exhaust gas air/fuel ratio such as a linear oxygen sensor or UEGO (universal or wide-range exhaust gas oxygen), a two-state oxygen sensor or EGO, a HEGO (heated EGO), a NOx, HC, or CO sensor.
  • Emission control devices 71 , 72 are shown arranged along exhaust passage 48 downstream of exhaust gas sensor 126 .
  • Devices 71 , 72 may be a three way catalyst (TWC), NOx trap, various other emission control devices, or combinations thereof.
  • emission control devices 71 , 72 may be periodically reset by operating at least one cylinder of the engine within a particular air/fuel ratio.
  • Controller 12 is shown in FIG. 1 as a microcomputer, including microprocessor unit 102 , input/output ports 104 , an electronic storage medium for executable programs and calibration values shown as read only memory chip 106 in this particular example, random access memory 108 , keep alive memory 110 , and a data bus.
  • Controller 12 may receive various signals from sensors coupled to engine 10 , in addition to those signals previously discussed, including intake gas concentration from sensor 24 ; measurement of inducted mass air flow (MAF) from mass air flow sensor 120 ; engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114 ; a profile ignition pickup signal (PIP) from Hall effect sensor 118 (or other type) coupled to crankshaft 40 ; throttle position (TP) from a throttle position sensor; and absolute manifold pressure signal, MAP, from sensor 122 .
  • Engine speed signal, RPM may be generated by controller 12 from signal PIP.
  • Manifold pressure signal MAP from a manifold pressure sensor may be used to provide an indication of vacuum, or pressure, in the intake manifold.
  • the MAP sensor can give an indication of engine torque. Further, this sensor, along with the detected engine speed, can provide an estimate of charge (including air) inducted into the cylinder.
  • sensor 118 which is also used as an engine speed sensor, may produce a predetermined number of equally spaced pulses every revolution of the crankshaft.
  • Storage medium read-only memory 106 can be programmed with computer readable data representing instructions executable by processor 102 for performing the methods described below as well as other variants that are anticipated but not specifically listed.
  • FIG. 2 shows only one cylinder of a multi-cylinder engine, and that each cylinder may similarly include its own set of intake/exhaust valves, fuel injector, spark plug, etc.
  • an exhaust gas recirculation (EGR) system may route a desired portion of exhaust gas from exhaust passage 48 to intake manifold 44 via EGR passage 170 .
  • the amount of EGR provided to intake manifold 44 may be varied by controller 12 via EGR valve 174 .
  • an EGR sensor 172 may be arranged within the EGR passage and may provide an indication of one or more pressure, temperature, and concentration of the exhaust gas.
  • the EGR system may be used to regulate the temperature of the air and fuel mixture within the combustion chamber, thus providing a method of controlling the timing of ignition during some combustion modes.
  • a portion of combustion gases may be retained or trapped in the combustion chamber by controlling exhaust valve timing, such as by controlling a variable valve timing mechanism.
  • the system of FIGS. 1 and 2 may provide for an engine system comprising a cylinder, a fuel injection system, an intake system coupled to the cylinder and including an oxygen sensor, and a control system including instructions to adjust fuel injection amount based on an external fuel concentration in the intake system, the external fuel comprising fuel from a positive crankcase ventilation system, fuel from a fuel vapor canister, and/or fuel evaporated from an intake valve and/or intake port.
  • Routine 300 may be carried out by a controller, such as controller 12 , in response to feedback from various sensors of the engine system, such as intake gas sensor 24 .
  • fuel injection parameters are determined based on engine operating parameters.
  • the fuel injection parameters may include fuel injection amount and timing, as well as other parameters such as spark timing.
  • the fuel injection parameters may be based on engine speed, engine load, manifold absolute temperature, engine temperature, etc. Further, the fuel injection parameters may be adapted based on feedback from one or more downstream air/fuel ratios, such as sensor 126 .
  • a desired air/fuel ratio such as a stoichiometric air/fuel ratio, may be determined based on the various engine operating parameters, and the fuel amount injected may be adapted based on the air/fuel ratio determined by the downstream sensors in order to maintain the desired air/fuel ratio.
  • the concentration of oxygen in the intake is determined based on a gas sensor in the intake.
  • routine 300 proceeds to 307 to maintain the current fueling parameters determined at 302 . If the measured oxygen concentration is different from the baseline concentration, routine 300 proceeds to 308 to determine the intake fuel concentration based on the intake oxygen concentration. As shown in FIG. 5 , any deviations from a predetermined level of ambient oxygen in the intake air may be attributed to fuel present in the intake. For example, ambient oxygen levels may be around 20%, as measured by the intake oxygen sensor when no fuel (or EGR) is present in the intake. An intake oxygen sensor reading of 16% may indicate that 1% of the intake volume is comprised of fuel, for example.
  • Determining the intake fuel concentration may include, in some conditions, correcting the fuel concentration based on operating parameters at 310 .
  • EGR present in the intake may lower intake oxygen concentration, and ambient humidity in the air may also alter intake oxygen amounts.
  • the intake fuel may derive from multiple sources, such as from the PCV system, fuel puddles on the intake ports, and pushback fuel arising during certain events such as intake/exhaust valve overlap. While the oxygen sensor may be able to detect fuel from all these sources, under some conditions the sensor may not detect them all, or may be subject to too much noise to accurately determine the fuel concentration. Additionally, adaptive fuel strategies may compensate for evaporating fuel from a fuel puddle that is then also measured by the intake gas sensor, resulting in fueling errors. The conditions likely to confound the determination of the fuel concentration, and mechanisms for correcting the fuel concentration based on the conditions, are discussed in more detail below with respect to FIGS. 4A-4C .
  • the fuel injection parameters set at 302 may be adjusted based on the determined intake fuel concentration. Adjusting the fuel injection may include adjusting a fuel injection amount at 314 . If the intake air includes an appreciable amount of fuel, the fuel injection amount may be reduced to compensate for this additional fuel. Additionally, because the intake fuel is likely to already be vaporized and homogenized by the time it enters the cylinder, under some conditions, the dynamics of when the fuel is injected and ignited may be altered as a result of the fuel in the intake. Further, the intake gas sensor may be able to detect EGR and/or humidity, and these factors may also effect injection and spark timing. Thus, to maintain optimal combustion conditions, fuel injection may be adjusted at 316 and spark timing may be adjusted at 318 . Upon either maintaining fuel injection at 307 or adjusting fuel injection at 312 , routine 300 ends.
  • FIGS. 4A-4C depict a routine 400 for correcting a fuel concentration determination in the intake of the engine.
  • Routine 400 may be carried out by the controller during the execution of routine 300 , for example at 310 , described above with respect to FIG. 3 .
  • routine 400 includes, at 402 , determining engine operating conditions.
  • the determined engine operating conditions may include engine speed, load, temperature, number of engine cycles since engine start, camshaft position, fuel injection amount and timing, spark timing, etc.
  • EGR is not enabled
  • routine 400 it is determined if the engine is in cold start conditions. This may include engine temperature being below a threshold, e.g., 100° F., and/or being less than a threshold number of cycles since engine start, such as 100 cycles. If it is determined that the engine is in cold start conditions, routine 400 proceeds to 408 to set the measured intake oxygen amount as a baseline oxygen concentration, which also includes oxygen present from the ambient humidity in the air. This baseline oxygen concentration may be stored in the memory of the controller for use in determining the fuel concentration in the intake, which will be described in more detail below with respect to FIGS. 4B and 4C . If the engine is not in cold start conditions, routine 400 proceeds to 438 of FIG. 4C , which will be described in more detail below.
  • FIG. 4B depicts a subset of routine 400 in which intake oxygen concentration may be used to determine intake fuel concentration and/or the EGR percentage in the intake, while EGR is enabled.
  • the operating conditions indicate there may be pushback fuel in the intake.
  • Example conditions which may arise in pushback fuel include positive intake/exhaust valve overlap, late intake valve closing, and one or more fuel puddles in an intake port or valve that is changing in size due to evaporation of the fuel puddle at a greater rate than fuel accumulation in the puddle. These may be determined by the position of the camshaft, or position of the intake valves, relative to piston position.
  • Pushback fuel conditions may also be determined by the amount and timing of fuel injections in the previous engine cycles.
  • routine 400 proceeds to 412 to estimate EGR percentage in the intake based on EGR valve position, MAP, MAF, etc. Because both EGR and pushback fuel are present in the intake, the measured oxygen concentration indicates reduction in oxygen concentration from both fuel in the intake and EGR. EGR percentage may be estimated so that the remaining reduction in oxygen concentration may be attributed just to the fuel in the intake. Thus, at 414 , the oxygen concentration reading may be corrected by the estimated EGR percentage.
  • Purge conditions may include the fuel vapor canister being in a regeneration state, e.g., the canister may be at its capacity to store fuel vapors. This may be determined by a position of a valve controlling the fuel vapor canister, or by an amount of time since a previous purge.
  • Fuel from the PCV system may be present in the intake when oil temperature is below standard warmed up temperature, and so may be present if engine temperature is below a threshold (such as the cold start temperature discussed above with respect to 406 of FIG. 4A ). Determination of whether fuel in the intake from the PCV system is present may be based on a position of the crankcase ventilation valve.
  • routine 400 proceeds to 418 to attribute the measured change in oxygen concentration from a baseline oxygen concentration to all external fuel sources, including fuel from pushback and from PCV and/or purge.
  • the intake oxygen sensor cannot differentiate these sources from each other, but can adjust the fuel injection amount based on the total fuel concentration in the intake. However, the relative contribution of each source may be determined under other conditions, which will be described in more detail below.
  • routine 400 proceeds to 420 to attribute the change in oxygen concentration in the intake from a baseline concentration to fuel from pushback only.
  • routine 400 proceeds to 422 to determine if conditions for purge and/or PCV are present, similar to the conditions determined at 416 . If purge and/or PCV fuel are present in the intake, routine 400 proceeds to 428 to estimate EGR percentage based on EGR valve position and other intake flow parameters. At 430 , the oxygen sensor reading is corrected to account for the estimated EGR percentage. At 432 , the change in oxygen concentration detected by the sensor is attributed to vapors from purge and/or PCV only.
  • routine 400 proceeds to 434 attribute the change in oxygen concentration detected by the sensor to the EGR present in the intake. As no fuel is present in the intake, this reading may be used directly to monitor the EGR percentage in the intake and used to adjust the EGR valve at 436 to maintain a desired EGR percentage in the intake. After determining what fuel sources are present in the intake at 418 , 420 , or 432 , or after adjusting the EGR valve at 436 , routine 400 exits.
  • FIG. 4B depicts a subset of routine 400 that may be used when EGR is enabled, to correct the oxygen sensor reading for the EGR in the intake.
  • any additional changes to the oxygen concentration in the intake not due to the EGR may be attributed to fuel sources such as a fuel vapor canister purge, PCV system, or from pushback.
  • the source of the fuel in the intake may be determined.
  • the overall change in the oxygen concentration may be caused by both the EGR and fuel sources in the intake, thus the EGR amount in the intake is estimated, and the remaining oxygen concentration attributed to the fuel sources in the intake.
  • These fuel sources may also be estimated based on predetermined fuel amounts expected to be present in the intake during various operating conditions.
  • the subset of routine 400 discussed with respect to FIG. 4C , may be performed when EGR is not enabled to determine the amounts of each of the fuel sources.
  • FIG. 4C depicts routine 400 following the determination at 406 that EGR is not enabled and that the engine is not in cold start conditions.
  • routine 400 proceeds to 440 to determine if vapors from purge and/or PCV are present. If so, at 442 , the change in oxygen concentration from baseline is attributed to all fuel sources, which cannot be differentiated from each other. However, if conditions for either canister purge or PCV fuel are not present, at 444 , the change in oxygen concentration detected may be attributed to only fuel from pushback. This measured amount may be stored in the memory of the controller for future use in modeling fuel amounts present in the intake.
  • routine 400 proceeds to 446 to determine if canister purge vapors and/or PCV fuel is present in the intake. If yes, routine 400 proceeds to 448 to determine if the engine is operating at idle or low load conditions. During idle or low load conditions, the amount of airflow through the intake is relatively low compared to higher load operating conditions. As a result, if the fuel vapor canister is in a purge condition, the purge flow may comprise a significant enough proportion of the airflow to be accurately measured by the oxygen sensor. If the engine is not operating in idle or low load, the conditions may not be optimal for accurate purge flow determination, and routine 400 proceeds to attribute the fuel in the intake to purge and/or PCV at 454 , without storing the determination for future use.
  • routine 400 proceeds to 452 to attribute the change in measured oxygen concentration to fuel only from the fuel vapor canister purge, and store this amount in memory for future use.
  • routine 400 proceeds to 454 to attribute the fuel in the intake to purge and/or PCV.
  • this amount may be subtracted out from the amount determined at 454 , and the remaining amount attributed to just fuel from the PCV system.
  • routine 400 Upon determining the source of the fuel in the intake at 442 , 444 , 452 , or 454 , or determining there is no fuel in the intake 456 , routine 400 exits.
  • routine 400 as depicted in FIGS. 4A-4C may provide various mechanisms for determining the source or sources of fuel present in the intake. Further, routine 400 may determine if EGR is present in the intake. This information may be based on readings from an oxygen sensor present in the intake and further based on various engine operating parameters. This information may then be used to adjust fuel injection in order to maintain the air/fuel ratio in the cylinders at a desired air/fuel ratio.
  • Intake oxygen readings can be used to provide information on various parameters, including ambient humidity, the amount of EGR in the intake, and the amount of fuel vapors in manifold (from fuel vapor, PCV, and/or pushback).
  • intake oxygen can provide information on each of the above singly. For example, when EGR is disabled and there is no canister vapor purge and no PCV, the intake oxygen reading provides the amount of fuel in the intake from pushback. When EGR is disabled and there is no pushback or PCV fuel in the intake, the intake oxygen reading provides the amount of fuel in the intake from the fuel vapor canister purge. In another example, when EGR is enabled but there is no fuel from a canister purge, pushback or the PCV system, the intake oxygen reading may provide the amount of EGR in the intake.
  • this determined concentration can be used to directly determine the amount of fuel in the intake from that source, and that amount stored in the memory of the controller.
  • Each of the above factors that affect the intake oxygen concentration may also be modeled, e.g., EGR flow may be modeled from EGR pressures and/or valve position, pushback can be estimated from valve timing and fuel injection parameters from the previous cycle, etc.
  • the senor may have a low signal-to-noise ratio and thus not provide an accurate determination of the intake fuel amount.
  • the amount of fuel vapors released to the intake during a purge can be estimated based on previous determinations in better conditions, and the amount of pushback modeled based on valve timing and fuel injection parameters from the previous cycle, to provide an estimation of the fuel present in the intake.
  • routines of FIGS. 3 and 4 A- 4 C may provide for a method comprising, during purging of fuel vapors from a fuel vapor storage system, adjusting fuel injection to an engine based on an amount of fuel vapors indicated from an intake oxygen amount measured by a sensor; and fuel pushback into the intake only during positive valve overlap.
  • 3 and 4 A- 4 C may also provide a method comprising, during EGR operation without fuel-vapor purging, adjusting an EGR valve to maintain a desired EGR amount, during fuel vapor purging without EGR, adjusting fuel injection based on intake oxygen concentration to maintain a desired air-fuel ratio, and during pushback without fuel vapor purging and without EGR, adjusting fuel injection based on intake oxygen concentration to compensate for fuel pushback from other cylinders.
  • adjusting the EGR valve may comprise during pushback, adjusting the EGR valve to decrease EGR percentage by a first amount based on a decrease in intake oxygen concentration, and without pushback, adjusting the EGR valve to decrease EGR percentage by a second amount, greater than the first, based on the decrease in intake oxygen concentration. In this way, the EGR valve may be adjusted based on the determined intake oxygen concentration. If the intake air includes fuel vapors from pushback, for example, the EGR valve may adjusted by a different amount than if the intake air does not include fuel vapors, for the same determined intake oxygen concentration.
  • the method may further comprise, during fuel vapor purging with EGR, adjusting fuel injection based on intake oxygen concentration and further based on an estimated EGR flow. In some embodiments, this may further comprise correcting the intake oxygen concentration for the estimated EGR flow, and if the corrected intake oxygen concentration is lower than a baseline oxygen concentration, then decreasing a fuel injection amount.
  • the method may comprise adjusting fuel injection based on intake oxygen concentration and fuel pushback into the intake during positive valve overlap, and the adjusting fuel inject may further comprise decreasing a fuel injection amount if the intake oxygen concentration is less than a baseline oxygen concentration.
  • the fuel injection amount may be decreased if the measured intake oxygen concentration is less than a baseline oxygen concentration.
  • a decrease in the oxygen concentration from baseline is indicative of fuel vapors present in the intake, and thus the fuel injection amount may be decreased to compensate for the fuel in the intake.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Supplying Secondary Fuel Or The Like To Fuel, Air Or Fuel-Air Mixtures (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)
US13/356,843 2012-01-24 2012-01-24 Method for injecting fuel Active 2032-10-25 US8838363B2 (en)

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US13/356,843 US8838363B2 (en) 2012-01-24 2012-01-24 Method for injecting fuel
RU2013100987A RU2609016C2 (ru) 2012-01-24 2013-01-10 Способ впрыска топлива (варианты)
DE102013200830A DE102013200830A1 (de) 2012-01-24 2013-01-21 Verfahren zum einspritzen von kraftstoff
CN201310027468.5A CN103216351B (zh) 2012-01-24 2013-01-24 喷射燃料的方法

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Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013065149A1 (ja) * 2011-11-02 2013-05-10 トヨタ自動車株式会社 内燃機関の制御装置
US9382861B2 (en) * 2013-02-22 2016-07-05 Ford Global Technologies, Llc Humidity Sensor Diagnostics
US9188087B2 (en) 2013-03-07 2015-11-17 Ford Global Technologies, Llc Ejector flow rate computation for gas constituent sensor compensation
US9273602B2 (en) 2013-03-07 2016-03-01 Ford Global Technologies, Llc Intake air oxygen compensation for EGR
US9631567B2 (en) * 2013-08-15 2017-04-25 GM Global Technology Operations LLC Sensor based measurement and purge control of fuel vapors in internal combustion engines
US9845754B2 (en) * 2013-12-23 2017-12-19 Cummins Inc. Control of internal combustion engines in response to exhaust gas recirculation system conditions
US9234476B2 (en) * 2014-04-14 2016-01-12 Ford Global Technologies, Llc Methods and systems for determining a fuel concentration in engine oil using an intake oxygen sensor
US9394843B2 (en) * 2014-10-10 2016-07-19 Ford Global Technologies, Llc Method for reducing engine oil dilution
DE102015217730A1 (de) * 2015-09-16 2017-03-16 Robert Bosch Gmbh Verfahren zum Betreiben einer Brennkraftmaschine
US10570850B2 (en) * 2016-01-14 2020-02-25 Nissan Motor Co., Ltd. Control method and control device of direct-injection internal combustion engine
US9995234B2 (en) * 2016-03-21 2018-06-12 Ford Global Technologies, Llc Methods and systems for engine fuel and torque control
CN106837614B (zh) * 2017-01-22 2019-05-24 浙江吉利动力总成有限公司 一种低压废气再循环控制系统及方法
JP7176301B2 (ja) * 2018-08-29 2022-11-22 株式会社デンソー 内燃機関システム

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4727849A (en) 1986-04-24 1988-03-01 Mitsubishi Denki Kabushiki Kaisha Exhaust gas recirculation control system for an internal combustion engine
US4823760A (en) * 1987-05-21 1989-04-25 Mitsubishi Denki Kabushiki Kaisha Internal combustion engine controlling apparatus
US5331940A (en) * 1992-03-09 1994-07-26 Unisia Jecs Corporation Engine control with positive crankcase ventilation
US6000385A (en) * 1996-11-14 1999-12-14 Toyota Jidosha Kabushiki Kaisha Combustion engine with EGR apparatus
US20020029768A1 (en) * 2000-09-08 2002-03-14 Takuji Matsubara Fuel injection control apparatus and method of direct fuel injection-type spark ignition engine
US20020139360A1 (en) 2001-03-05 2002-10-03 Fumihiko Sato Combustible-gas sensor, diagnostic device for intake-oxygen concentration sensor, and air-fuel ratio control device for internal combustion engines
US20030106530A1 (en) * 2001-12-12 2003-06-12 Honda Giken Kogyo Kabushiki Kaisha Control system for internal combustion engine
US7150264B2 (en) * 2003-12-25 2006-12-19 Denso Corporation Control device for internal combustion engine
JP2006342786A (ja) * 2005-06-10 2006-12-21 Toyota Motor Corp 多気筒ガソリンエンジン
US20070044472A1 (en) 2005-09-01 2007-03-01 Guoqing Zhang Oxygen sensor for an internal combustion engine
US20070119420A1 (en) * 2005-11-30 2007-05-31 Leone Thomas G Method for controlling injection timing of an internal combustion engine
US20070283933A1 (en) * 2006-06-12 2007-12-13 Steve Magner System and Method of Controlling Fuel Delivery During Positive Valve Overlap Operation of an Engine Start
US8036812B2 (en) * 2009-08-06 2011-10-11 Ford Global Technologies, Inc. Method for controlling an internal combustion engine

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3496468B2 (ja) * 1997-08-08 2004-02-09 日産自動車株式会社 内燃機関の蒸発燃料濃度判定装置
RU2177553C2 (ru) * 1999-10-12 2001-12-27 Открытое акционерное общество "Заволжский моторный завод" Быстроходный дизельный двигатель с непосредственным впрыском топлива
JP2006291916A (ja) * 2005-04-14 2006-10-26 Toyota Motor Corp 駆動システムおよびこれを搭載する自動車並びに駆動システムの制御方法
EP1770265A3 (en) * 2005-09-30 2011-02-23 Honda Motor Co., Ltd. EGR control system for internal combustion engine
JP4656092B2 (ja) * 2007-06-11 2011-03-23 トヨタ自動車株式会社 内燃機関の制御装置
US7809491B1 (en) * 2009-05-26 2010-10-05 Ford Global Technologies, Llc Method to perform carbon canister purge and adaption of air-fuel ratio estimation parameters

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4727849A (en) 1986-04-24 1988-03-01 Mitsubishi Denki Kabushiki Kaisha Exhaust gas recirculation control system for an internal combustion engine
US4823760A (en) * 1987-05-21 1989-04-25 Mitsubishi Denki Kabushiki Kaisha Internal combustion engine controlling apparatus
US5331940A (en) * 1992-03-09 1994-07-26 Unisia Jecs Corporation Engine control with positive crankcase ventilation
US6000385A (en) * 1996-11-14 1999-12-14 Toyota Jidosha Kabushiki Kaisha Combustion engine with EGR apparatus
US20020029768A1 (en) * 2000-09-08 2002-03-14 Takuji Matsubara Fuel injection control apparatus and method of direct fuel injection-type spark ignition engine
US6371086B1 (en) * 2000-09-08 2002-04-16 Toyota Jidosha Kabushiki Kaisha Fuel injection control apparatus and method of direct fuel injection-type spark ignition engine
US20020139360A1 (en) 2001-03-05 2002-10-03 Fumihiko Sato Combustible-gas sensor, diagnostic device for intake-oxygen concentration sensor, and air-fuel ratio control device for internal combustion engines
US6739177B2 (en) 2001-03-05 2004-05-25 Toyota Jidosha Kabushiki Kaisha Combustible-gas sensor, diagnostic device for intake-oxygen concentration sensor, and air-fuel ratio control device for internal combustion engines
US20030106530A1 (en) * 2001-12-12 2003-06-12 Honda Giken Kogyo Kabushiki Kaisha Control system for internal combustion engine
US7150264B2 (en) * 2003-12-25 2006-12-19 Denso Corporation Control device for internal combustion engine
JP2006342786A (ja) * 2005-06-10 2006-12-21 Toyota Motor Corp 多気筒ガソリンエンジン
US20070044472A1 (en) 2005-09-01 2007-03-01 Guoqing Zhang Oxygen sensor for an internal combustion engine
US20070119420A1 (en) * 2005-11-30 2007-05-31 Leone Thomas G Method for controlling injection timing of an internal combustion engine
US20070283933A1 (en) * 2006-06-12 2007-12-13 Steve Magner System and Method of Controlling Fuel Delivery During Positive Valve Overlap Operation of an Engine Start
US8036812B2 (en) * 2009-08-06 2011-10-11 Ford Global Technologies, Inc. Method for controlling an internal combustion engine

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CN103216351B (zh) 2017-05-03
US20130191008A1 (en) 2013-07-25
CN103216351A (zh) 2013-07-24
RU2013100987A (ru) 2014-07-20
RU2609016C2 (ru) 2017-01-30

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